A photosensitive resin layer is exposed to light through a pattern and developed to produce a signboard and the like. Photosensitive resin laminates made by the use of a photosensitive resin are disclosed in JP-A-58-55927, JP-A-9-6267 and the like and used for display panels having a relief, signboards containing Braille and the like.
However, signboards for use in these days are required to stand bending during processing, to be transparent and the like. Moreover, the need for good designs of signboards is increasing in recent years, to the point that a conventional simple signboard having a typical concavo-convex pattern colored with a color paint is not satisfactory.
However, a photosensitive resin laminate for general use, which comprises a phenol board as a support, is not suitable for bending during processing of a signboard or preparation of a transparent signboard. Even when a transparent and colorless substrate is used as a support, the photosensitive resin itself is colored. Moreover, it is colored when placed near a window due to the UV light. Accordingly, there has arisen a demand on a photosensitive resin laminate suitable for processing into a signboard having a good design.
A photosensitive resin composition contains a naphthoquinone compound and the like for the purpose of inhibiting thermal polymerization and for adjusting sensitivity and the like. Because of the color of these compounds, the use of these compounds inevitably results in a colored photosensitive resin composition, which is problematic for the production of a signboard having a superior design. Even if the amount of addition of these compounds is reduced with the hope of suppressing the coloring, the polymer tends to become a gel during the production, thus practically preventing the production.
It is therefore an object of the present invention to provide a photosensitive resin laminate for signboards usable for display panel, decoration shield, name plate, Braille board and the like, which laminate has a superior design, which can be bent during processing of a signboard, and from which a transparent signboard can be produced, as well as a plate for a signboard and a signboard, which are made of this resin laminate, which have superior design and superior resistance to light, and which show lower degrees of coloring by UV.